Yacon roots (Smallanthus sonchifolius) improve oxidative stress in diabetic rats

Figures & data

Table 1. Effect of yacon treatment (90 d) on blood glucose and plasma insulin levels under fasting conditions.

	Fasting glucose levels (mg/dl)		Fasting insulin levels (ng/ml)
Animal groups	Pre-treatment	Post-treatment	Pre-treatment	Post-treatment
NC	87.5 ± 1.5	89.1 ± 1.9	3.57 ± 0.71	2.97 ± 0.53
DC	371.5 ± 3.5^a	455.9 ± 8.7^a,c	0.19 ± 0.13^a	0.17 ± 0.07^a
DY340	353.3 ± 7.3^a	351.1 ± 3.7^a,b	0.21 ± 0.10^a	0.77 ± 0.03^a,b,c

Data are the mean ± SD. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root (340 mg FOS/kg body weight).

^ap < 0.05 compared with non-diabetic control animals.

^bp < 0.05 compared with the diabetic control group.

^cp < 0.05 compared with pre-treatment levels within the same group.

Table 2. Terminal clinical chemistry in rats after 90 d of yacon-supplement feeding.

Animal groups	Total cholesterol (mg/dl)	Triacylglycerol (mg/dl)	AST (IU/L)	ALT (IU/L)	Creatinine (mg/dl)
NC	65.0 ± 3.3	90.0 ± 4.5	184.50 ± 24.75	50.00 ± 2.83	0.35 ± 0.05
DC	135.7 ± 22.5^a	385.5 ± 61.5^a	268.50 ± 27.02^a	94.33 ± 4.51^a	0.78 ± 0.03^a
DY340	98.2 ± 17.7^a	127.5 ± 53.0^b	222.50 ± 17.23^a,b	81.50 ± 6.66^a,b	0.67 ± 0.05^a,b

Data are the mean ± SD. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root (340 mg FOS/kg body weight).

^ap < 0.05 compared with non-diabetic control animals.

^bp < 0.05 compared with the diabetic control group.

Table 3. Levels of total cholesterol and free fatty acids in liver homogenates at the end of the experimental period.

Animal groups	Total cholesterol (μg/g tissue)	Free fatty acids (μg/g tissue)
NC	10.46 ± 1.64	21.67 ± 1.08
DC	21.47 ± 6.08^a	40.00 ± 2.00^a
DY340	16.39 ± 1.56^a	25.56 ± 1.28^a,b

Data are the mean ± SD. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

^ap < 0.05 compared with non-diabetic control animals.

^bp < 0.05 compared with diabetic control animals.

Figure 1. Effect of yacon root flour (340 mg FOS/kg body weight) on fatty acid composition (μg/g) in the liver of STZ-diabetic rats. Data are the mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

Figure 2. Effect of yacon root flour (340 mg FOS/kg body weight) on malondialdehyde (MDA) concentrations in (a) liver and (b) kidney of normal and STZ-diabetic rats. Data are the mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

Table 4. Effects of treatment with yacon root flour for 90 d on liver CAT, SOD and GPx activities as well as GSH and MDA levels of normal and diabetic rats.

	Liver
Parameters	NC	DC	DY340
MDA (nmoles/mg protein)	53.60 ± 2.68	84.27 ± 421^a	58.17 ± 2.90^b
% of change from NC		57.22
% of change from DC			−30.97
CAT (U/mg protein)	186.00 ± 9,30	206.31 ± 10.31^a	73.59 ± 3.67^a,b
% of change from NC		10.92
% of change from DC			−64.33
SOD (U/mg protein)	23.17 ± 1.15	26.52 ± 1.32^a	22.95 ± 1.26^b
% of change from NC		14.46
% of change from DC			−13.46
GPx (µg GSH/min/mg protein)	1.75 × 10^−2± 0.08 × 10^−2	0.80 × 10^−2 ± 0.04 × 10^−2a	2.18 × 10^−2 ± 0.10 × 10^−2a,b
% of change from NC		−54.28
% of change from DC			172.5
GSH (mg GSH/g tissue)	53.30 ± 2.66	40.79 ± 2.03^a	55.44 ± 2.77^b
% of change from NC		−23.47
% of change from DC			35.91

All data are the means of six animals ± SD. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

^ap < 0.05 compared with the non-diabetic control group.

^bp < 0.05 compared with the diabetic control group.

Table 5. Effects of treatment with yacon root flour for 90 d on kidney CAT, SOD, and GPx activities as well as GSH and MDA levels of normal and diabetic rats.

	Kidney
Parameters	NC	DC	DY340
MDA (nmoles/mg protein)	48.43 ± 2.42	64.43 ± 3.22^a	52.09 ± 2.60^b
% of change from NC		33.03
% of change from DC			−19.15
CAT (U/mg protein)	127.00 ± 6.35	157.28 ± 7.86^a	120.00 ± 6.00^b
% of change from NC		23.84
% of change from DC			−23.70
SOD (U/mg protein)	25.59 ± 1.27	43.58 ± 2.17^a	36.51 ± 1.82^a,b
% of change from NC		70.30
% of change from DC			−16.22
GPx (µg GSH/min/mg protein)	1.67 × 10^−2 ± 0.08 × 10^−2	0.90 × 10^−2 ± 0.04 × 10^−2a	2.50 × 10^−2 ± 0.12 × 10^−2a,b
% of change from NC		−46.11
% of change from DC			177.78
GSH (mg GSH/g tissue)	32.11 ± 1.60	28.55 ± 1.42^a	45.04 ± 1.87^a,b
% of change from NC		−11.09
% of change from DC			57.76

All data are the means of six animals ± SD. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

^ap < 0.05 compared with the non-diabetic control group.

^bp < 0.05 compared with the diabetic control group.

Figure 3. Effect of yacon root flour (340 mg FOS/kg body weight) on catalase (CAT) activity in (a) liver and (b) kidney of normal and STZ-diabetic rats. Data are the mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

Figure 4. Effect of yacon root flour (340 mg FOS/kg body weight) on superoxide dismutase (SOD) activity in (a) liver and (b) kidney of normal and STZ-diabetic rats. Data are the mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

Figure 5. Effect of yacon root flour (340 mg FOS/kg body weight) on glutathione peroxidase (GPx) activity in (a) liver and (b) kidney of normal and STZ-diabetic rats. Data are the mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).

Figure 6. Effect of yacon root flour (340 mg FOS/kg body weight) on reduced glutathione (GSH) concentration in (a) liver and (b) kidney of normal and STZ-diabetic rats. Data are mean ± SD. ^ap < 0.05 compared with non-diabetic control animals; ^bp < 0.05 compared with diabetic control animals. n = 6 animals per group. NC, non-diabetic control animals; DC, diabetic control animals; DY₃₄₀, diabetic animals treated with yacon root flour (340 mg FOS/kg body weight).